1. Field of the Invention
The present invention relates to a pigtailed or fiber connector for a fiber laser. More particularly, the present invention provides a pigtailed structure that may be used to alter spatial distribution of output beam.
2. Description of the Related Art
Referring now to FIG. 1, typically, high power fiber lasers have one or a plurality of component known as a fiber connector, shown generally at 100. The connector 100 is operative to output radiation from a laser system. The output radiation may further propagate over the free space along a light path and either be coupled into a downstream laser component or perform the task at hand.
Connector 100 includes a ferrule 105, partially enclosing a block 102 made from quarts and having a cylindrical shape and a flat front (upstream or input) facet 106 and a flat back (downstream or output) facet 103. The upstream facet 106 is fused to a downstream facet of core 101 which is part of a fiber 101A that also has a cladding surrounding the core 101 upstream from the ferrule 105.
The flat surface of downstream facet 103 of block 102 is as disclosed in U.S. Pat. No. 5,619,602 (Sandstrom et al.) the entire content of which is incorporated herein by reference. As shown, the block facets 106, 103 have a planarity surface, defined as planar or required to be flat to operate.
The optical fiber 100A supports a beam output from the downstream core end of core 101 into the block 102. The beam tends to diverge from front facet 106 of block 102. As the beam continues to propagate along the block 102, its diameter gradually increases while its power density progressively decreases. Consequently, the power density of the beam at the downstream black's facet 103, which extends from the downstream end of the ferrule 105, is substantially lower than that at the output of core 101. The relatively low power density of the output radiation 104 allows covering of the outer face of the facet 103 with an an anti-reflection coating which prevents backreflected light, which may reach kW levels in high power laser systems, from damaging block 102.
The output radiation 104, as shown, is also divergent. Yet typically, the radiation 104 should be either collimated or focused which requires additional optical components, as well known to one of ordinary skill in the art.